<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width,initial-scale=1.0">
  <title>index</title>
</head>
<body>

<div id="app">
  <!--插值表达式,或者叫 声明式渲染-->
  <h2>{{title}}</h2>
  <h4>我是: {{user.username}}, 今年{{user.age}}岁了. </h4>
</div>


<script src="vue.js"></script>
<script>
  new Vue({
    el: '#app',
    data: {
      title: '你好,世界!',
      user: {
        username: 'biege',
        age: 18
      }
    }
  })
</script>
</body>
</html>